Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Define how to prevent the cancer, Define How to Prevent the Cancer? A c...

Define How to Prevent the Cancer? A continuing and urgent need is there to take all steps to prevent cancer. Cancer rates are set to increase another 50 percent by the year 202

Reproduction, what is the difference between anaisogyami & oogyami?

what is the difference between anaisogyami & oogyami?

Define the water activity - microbial survival and growth, Define the Water...

Define the Water activity - Microbial Survival? It is the amount of water available to the organism. In general, requirement for water activity is more for bacteria (minimum 0.

Classify biomaterials and list some examples, Q. Classify biomaterials and ...

Q. Classify biomaterials and list some examples? Biologic classification is based on tissue response and systemic toxicity effects of the implant and is divided into three clas

Deciduous senescence - senescence, Deciduous Senescence - Senescence O...

Deciduous Senescence - Senescence Only the leaves senesce as in many trees. The senescence of leaves, or abscission occurs when at the base of a leaf a layer of cells is laid

Mechanism of enzyme action, Mechanism  of Enzyme Action  The action of...

Mechanism  of Enzyme Action  The action of enzymes is to lower  the activation energy  or threshold  of their substrates which. Therefore  become  activated and   react  with

What is the type of genetic inheritance of daltonism, What is the type of g...

What is the type of genetic inheritance of daltonism? Is daltonism more frequent in men or in women? What is the physiological explanation for the daltonism? Daltonism is a re

Explain basic functions of the micronucleus, Q. What are the respective fun...

Q. What are the respective functions of the micronucleus and of the macronucleus in the paramecium? The macronucleus is properly the cell nucleus it has RNA and DNA and acts as

Illustrate the types of Bone Remodeling, Illustrate the types of Bone Remod...

Illustrate the types of Bone Remodeling Bone remodeling occurs on existing bone surfaces. However, unlike modeling, remodeling cannot cause large changes in bone structure at a

Anatomy, Anatomy: Anatomy (from Greek words anatomia which means separate ...

Anatomy: Anatomy (from Greek words anatomia which means separate and temnein which means to cut open) is a branch of biology and which deals with the study of internal organizatio

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd